Down products filled with insulating materials such as duck down or goose down are used not only for cold weather clothing and bedding, but recently they are also getting lots of attention and well sought after as products for outdoor clothing or the like.
As to clothing or bedding products prepared by filling a wadding material between an outer fabric and an inner fabric, the filled wadding material may generate phenomena such as getting lumpy, moving around, getting stacked or the like while manufacturing or utilizing the products, which may cause various inconveniences. In a case that the wadding material is a fabric such as a cloth, the above phenomena can be prevented by fixing the edge of the wadding material to the edge of the product. In a case that the wadding material is a continuous material such as cotton or wool, the wadding material can be prevented from moving or getting lumpy by sewing the inner fabric and outer fabric together with the wadding material therebetween by backstitching or quilting.
In a case that the wadding material is a non-continuous material such as duck feathers or goose feathers, it is difficult to fix the wadding material by backstitching or quilting, but it is possible to prevent the wadding material from moving or getting lumpy by making separate rooms such as compartments between the inner fabric and the outer fabric.
A down compartment is generally formed by connecting an inner fabric and an outer fabric with combining or bonding lines for separating compartments, and the compartments (rooms) formed by the inner fabric, the outer fabric and the combining lines are filled with down (down feather). In a down jacket, sewing line compartment walls are formed at a certain interval by sewing the inner fabric together with the outer fabric, and then the opened ends of the inner fabric and outer fabric are subjected to an overlock finishing to form spatially closed down compartments.
Down products having one or more separated down compartments as above can prevent down from moving around or moving back, but still have other problems such as coming out of down and an introduction of moisture through the fabric itself, coming out of down and an introduction of moisture through sewing holes or needle holes, and an increase of manufacturing cost due to the sewing process for forming down compartments.
The coming out of down through the fabric itself can be prevented relatively easily by employing a down-proof processed fabric or a coated or laminated functional fabric. Functional fabrics such as a moisture-permeable waterproof fabric or a breathable fabric are prepared by a surface processing, a film coating or a multi-layer structuring, and can prevent the coming of down and the introduction of moisture through the fabric itself. Further, they can prevent a phenomenon that the down gets damp and a generation of bad smell due to the introduced moisture.
In order to prevent down from coming out and an introduction of moisture through sewing holes or needle holes, there have been proposed an intercalation sewing method wherein the sewing holes are closed by inserting an intercalation fabric or adhesion band between an inner fabric and an outer fabric and sewing them, a sewing-line sealing method wherein the coming out of down and introduction of moisture through the sewing holes is prevented by covering the sewing line with another fabric and then adhering/fusing its end parts to seal the sewing line, and a seamless bonding method wherein the fabrics are not sewn but combined by an adhering method or a fusing method.
Korean Patent Application No. 10-2004-0102619 suggested an intercalation sewing method wherein a fabric tape is intercalated along a sewing line. This document has disclosed that the coming out of duck feathers through needle holes of a sewing line could be prevented by an inserting process for placing a fabric tape along the (intended) sewing line and a sewing process along the inserted fabric tape. However, the inserting process and the sewing process are difficult to be mechanized and are a time- and manpower-consuming process, which makes the manufacturing cost high and a mass production difficult. In addition, after a long-term use, the fabric tape may lose its adhesiveness and then be separated from the inner fabric or outer fabric, thereby causing duck feathers to come out again through the needle holes of the sewing line. Further, it may be necessary to perform an additional step for fixing or pre-adhering the fabric tape so that it does not move during work.
Korean Patent Application Nos. 10-2009-0036839 and 10-2009-0036840 suggested an intercalation sewing method wherein a hot melt is intercalated along the sewing line. This document has disclosed that the coming out of duck feathers through the needle holes of the sewing line can be prevented by an inserting process for placing a hot melt band or belt along the (intended) sewing line and a sewing process along the inserted hot melt. However, the inserting process and the sewing process are difficult to be mechanized and are a time- and manpower-consuming process, which makes the manufacturing cost high and a mass-production difficult. In addition, after a long-term use, the hot melt may lose its adhesiveness and then be separated from the inner fabric or outer fabric, thereby causing duck feathers to come out again through the needle holes of the sewing line. Further, it may be necessary to perform an additional step for fixing or pre-adhering the hot melt so that it does not move during work.
Korean Patent Application No. 10-2007-0110839 discloses a seamless (or non-sewing) bonding method wherein an inner fabric and an outer fabric are bonded with a hot melt film with a specific pattern, and the space between said patterns is utilized as down compartments. The technology of this document has been suggested in order to solve the problems of prior art (e.g., Korean Patent Application No. 2004-0102619) wherein a plurality of down compartments are prepared by forming down compartment separation lines at a certain interval in the lateral direction by a sewing or a fabric tape. This document discloses that it is possible to utilize, as down compartment which can prevent the movement or sagging of duck feathers, a space formed with a hot melt film having a specific design. Said spaces can be separately divided by inserting and pre-adhering the hot melt film having a shape such as a specific diagram, letter or logo between an inner fabric and an outer fabric and fusing the inner fabric and the outer fabric by a hot-pressing. As the hot melt adhesive, mention can be made on a heat melt adhesive, which exists in a solid phase and stays in solid state without being dissolved or dispersed in a solvent at room temperature, but melts and changes into liquid upon receiving a certain amount of heat, thereby being able to adhere instantly. In this prior art technology, a hot melt film can increase the adhesion area as compared to a hot melt band or belt, and thus the adhesiveness can be increased. However, since fabrics are bonded by hot-pressing the heat melt adhesive, there are still problems that the pattern line finishing is not clear and thus the aesthetic value is low, and the fabric may get separated from the adhesive after a long-term use or a repeated use and/or during washing due to lack of adhesiveness durability.
Korean Patent Application No. 10-2010-0020559 discloses a seamless bonding method wherein a bonding line for compartment separation is formed by hot-fusing the surface of a fabric. This document discloses that, first, an inner fabric and an outer fabric are cut to give pattern pieces and the resulting pattern pieces are sewed at their edges to make a clothes piece where edges of the inner fabric and the outer fabric are combined but down compartments are not formed, and second, the space between the inner fabric and outer fabric of the clothes piece mentioned above is filled with down (duck feathers) and then the clothes piece is subjected to a hot fusion to form a bonding line for compartment separation while blowing compressed air so that duck feathers are not placed on the intended bonding line for compartment separation. However, the process of dividing or splitting the filled duck feathers into both sides of the intended bonding line and the process of blowing the compressed air so that duck feathers are not placed on the intended bonding line, etc. are complex, time- and manpower-consuming, and difficult to be mechanized, which makes difficult a mass production of down products. In addition, it is difficult to achieve an even distribution of down and the uniformity of down compartments, and therefore, the above method is difficult to be applied to actual production.
Korean Patent Application No. 10-2011-0015144 (PCT/KR2012/001261) discloses a seamless bonding method wherein a bonding line for compartment separation is formed by a hot-fusion of a fabric coating. This document discloses a down jacket and its preparation, wherein a urethane coating layer is formed on both of the inner surface of an inner fabric and the inner surface of an outer fabric which are made of a spandex material, and then compartments are formed by fusing the urethane coating layer of the inner surfaces along a bonding line without sewing. The fusing method of fabric coating, including the fusing method of the fabric itself, has fundamental problems that the fabric may be damaged and there is a limitation in the fabric that can be applied (i.e., limited to a fabric or fabric coating that can be fused). In addition, since fusing itself is a type of a melt-bonding of a copolymer resin, not a bonding by polymerization or graft, it has the same problem as a hot melt bonding method mentioned above. That is, there are problems that the pattern line finishing is not clear and thus the aesthetic value is low, and the fabric may get separated from the adhesive after a long-term use or a repeated use and/or during washing due to lack of adhesiveness durability.
Korean Utility Model Application No. 20-2006-0022001 discloses a seamless bonding method wherein a bonding line for compartment separation is formed by using an adhesive. This document suggests a method for preparing duck feather clothing wherein a double fabric is firstly prepared by introducing an adhesive in a wave shape between the inner fabric and outer fabric to form a wave-shaped adhesive part, and then the double fabric is cut and sewed in a desired shape. This document also describes that it is possible to prevent the loss of duck feathers through needle holes because an inner fabric and an outer fabric are bonded by an adhesive, and it is possible to prevent the duck feathers from moving back or from getting lumpy in the compartments divided by the wave-shaped adhesives. This prior art technology does not use a curing-reactive adhesive, but uses a solvent-dissolved solid adhesive, which is a melting-heat type adhesive such as hot melt. Thus, this prior art technology, like the hot melt bonding method mentioned in the above, still has problems that the pattern line finishing is not clear and thus the aesthetic value is low, and the fabric may get separated from the adhesive during long-term or repeated use and/or washing due to lack of adhesiveness durability.
Korean Patent Application No. 10-2011-0019556 also discloses a seamless bonding method wherein a bonding line for compartment separation is formed by using an adhesive. However, this document only describes that a common adhesive is employed as the adhesive and the adhesive is heat-treated to achieve the bonding, but does not have any detailed description concerning the type of adhesives and the bonding method.
Korean Patent Application No. 10-2011-0116426 discloses a sewing line closing method wherein the end parts of functional fabric such as moisture-permeable waterproof fabric is finished by using a seam sealing tape. This document describes that a sewing wrinkle generation phenomenon generated upon sewing and a coating face slip phenomenon of the moisture-permeable waterproof fabric due to a sewing needle can be solved by closing the sewing line of the end part of the fabric with the seam sealing tape, and that their tensile strength and waterproof performance are good. When closing and finishing the sewing line for compartment separation with the seam sealing tape according to the sewing line closing method, it is also possible to prevent an introduction of moisture through the sewing holes.
It is difficult to find prior art documents which disclose a sewing line closing method. However, many manufacturing companies prevent the introduction of moisture through sewing holes by closing the sewing line and the overlock finishing area by means of such a sewing line closing method. For example, there are attempts to prevent down from coming out by covering and closing the sewing line or the overlock finishing area with a fabric having the same color after manufacturing the down product by means of a sewing method (e.g. W.L. Gore & Associates). However, even this method has a problem that an additional process for closing the sewing line is required in addition to the sewing process for forming a compartment line.
In addition, in order to prevent the leaking of duck feathers and the entering of rainwater through the sewing holes, there are disclosed a method for closing the sewing holes by sewing using a melting thread and heat-fusing the melting thread (Korean Patent Application No. 10-2009-0126881), a technology of fusing with an ultrasonic fuser and finishing with a seam sealing tape (Korean Patent Application No. 10-2009-0126881), and the like.
Meanwhile, a new quilting method using a high-frequency heating has been suggested. For example, Japanese Patent Laid-Open No. 2000-328462 discloses a technology of inlaying a quilting pattern on the surface by introducing a curing-reactive liquid adhesive via an injection needle between an inner fabric and an outer fabric, and bonding the inner fabric, the intermediate layer and the outer fabric together by a high-frequency heating and pressing. This document discloses that, by high-frequency heating and pressing the curing-reactive liquid adhesive introduced into the intermediate layer, the fabric and the intermediate layer are press-bonded at the inside, and a pattern of a pressing tip is inlaid on the surface. However, since the liquid adhesive introduced into the inside can spread around during the pressing, the adhesion condition of the inside would vary and cannot be uniform. Thus, the finishing of the adhering line would be very poor and uneven. Further, the needle holes created when introducing the adhesive may be the cause of damage to the fabric and a penetration of moisture.
Meanwhile, in the field of manufacturing down products, the problems that down gets lumpy and moves around can be solved to some extent by forming compartments, whereas the additional sewing process for forming such compartments is manpower- and time-consuming and thus causes another problem that the process cost increases. Further, there is a problem that the sewing process is difficult to be mechanized and thus mass production of down products is difficult.
As a seamless bonding method that does not go through a manpower- and time-consuming sewing process, there have been suggested a bonding method using an adhesive and a fusing method by a fabric fusing. However, such bonding method and fusing method are also difficult to be mechanized, and thus became a manpower- and time-consuming process. Further, due to damage to the fabrics by a fabric fusing or the like, a limitation in selecting fabrics, and a lack of adhesive strength and durability with the heat-melting adhesion method, there have been limitations in putting these methods to practical use at actual manufacturing places.
Under such circumstances, research has continued to develop a method to form a compartment separation line between an inner fabric and an outer fabric by using an adhesive so as to cause no problem in adhesiveness, adhesiveness durability and adhering line finishing.